Phytophthora mediterranea

Name and publication

Phytophthora mediterranea Bregant, Mulas and Linaldeddu (2021)

Bregant C, Mulas AA, Rossetto G, Deidda A, Maddau L, Piras G, Linaldeddu BT. 2021. Phytophthora mediterranea sp. nov., a new species closely related to Phytophthora cinnamomi from nursery plants of Myrtus communis in Italy. Forests 12 (6): 682.





refers to the Mediterranean region, where the species was originally discovered


Type: ITALY, Oristano, isolated from roots of a potted plant of Myrtus communis, 18 April 2019, isolated by Antonio Mulas, HOLOTYPE CBS H-24768, a dried culture on CA

Ex-type: culture CBS 147720 = CB84

Sequences for ex-type in original manuscript:  ITS MW892398, ß-tubulin MW900443, cox1 MW900447

Molecular identification

Position in ITS phylogenetic tree

Clade 7c

Morphological identification

Colonies and cardinal temperatures

Colony morphology stellate on PDA, radiate on MEA, and cottony with no pattern on CA. Minimum growth temperature 10°C, optimum 32°C, and maximum 38°C.

Conditions for growth and sporulation

Sporangia produced in unsterile pond water after 36-48 h. Oogonia not formed in single or paired cultures.

Asexual phase

Sporangia were non-papillate, persistent, and predominantly ovoid to ellipsoid in shape with external proliferation. Sporangia averaged 43 x 30 µm (overall range 27–65 x 20–47 µm). Sporangiophores unbranched. Hyphal swellings present. Chlamydospores present, abundant.

Sexual phase

Sterile in culture.

Most typical characters

Phytophthora mediterranea is separated from related species P. cinnamomi and P. parvisora by its higher maximum and optimum temperature value for growth.

Additional specimen(s) evaluated

ITALY: Oristano, isolated from rhizosphere and fine roots of a potted plant of Myrtus communis, 12 November 2020, isolated by Carlo Bregant; culture CB85

Hosts and distribution

Distribution: Italy
Substrate: root and collar
Disease note: plants showed wilting foliage, chlorosis, stunted growth and sudden death symptoms in nurseries
Host: Myrtus communis

Additional references and links

none available

Fact sheet author

Treena Burgess, Ph.D., Phytophthora Science and Management, Harry Butler Institute, Murdoch University